1. Field of the Invention
This invention relates to symbol recognition and more particularly to systematically modifying the digital image of the symbol to enhance recognition reliability.
2. Description of the Prior Art
Heretofore, printed symbols have been recognized by the peep hole technique without enhancement. Inaccuracies inherent in the printing process create deviations between like numbers or letters which complicate the recognition process. The identical symbol may have a wide or thin stroke depending on the type-to-paper pressure, the characteristics of the paper, the condition of the type, the quantity of ink, etc. The myriads of slightly different type fonts compound the symbol deviation problem. Further, the process of forming a matrix image of photosensitive elements from the printed image is at best an approximation, the fidelity of which is limited by the resolution of the matrix. The deviations between like symbols increases the number of fine encoding points required to maintain an acceptable reject-error rate. The fine encoding point recongnition technique is described in more detail in U.S. Pat. No. 3,382,482 filed Oct. 17, 1961 by R. B. Greenly entitled, "Character Recognition System" and in a publication entitled "Optical Character Recognition Based on Peephole Template Matching" by Klaus. Maass appearing in Computer Design, December 1965, p. 18--23.